Overhead valve construction



1.. ROBERTISON 1,807,574

OVERHEAD VALVE CONSTRUCTION June 2, 1931.

Filed May 19, 1928 INVENTOR. Lqmgsncr. Eozlelfiou.

W I ATTORNE.

Patented June 2, 1931 LAWRENCE ROBERTSGN,

PATET OFFICE OF DETROIT, ILJIIGHIGAIT OVERHEAD VALVE CONSTRUCTION Application filed May 19,

Another object of the invention is the provision of a valve construction of this class whereby the intake port may be controlled by a valve positioned axially of the valve controlling the outlet port.

Another object of the invention is the provision of an exhaust control valve having a cylindrical stem forming portion and an inlet control valve positioned axially of the eX haust valve and engaging the end of the sleeve portion as a seat.

Another object of the invention is the provision in an engine of this class of a head and valve construction whereby an easy and quick assembly and disassembly of the various parts may be effected.

Gther objects will appear hereinafter.

The invention consists in the combination and arrangement of parts hereinafter described and claimed.

The invention will be best understood by a A reference to the accompanying drawings which form a part of this specification and in which,

Fig. 1 is a central vertical sectional view of the invention showing it applied to an engine.

Fig. 2 is a longitudinal sectional view in fragment of an engine embodying the invention.

Fig. 3 is a fragmentary sectional view taken on line 3-3 of Fig. 1.

Fig. 1 is a fragmentary sectional view taken on line 4-4 of Fig. 1.

In the drawings I have illustrated the invention applied to an engine having a cylinder block 9 and a head formed from the upper section 10 and the lower section 11, a

1928. Serial No. 278,949.

gasket 12 being interposed between the lower section 11 and the cylinder'block 9, and a gasket 13 being positioned between the upper section 10 and the lower section 11. An outlet port 14.- communicates with an exhaust chamber or manifold 14* formed in the section 11. Formed in the section 11 is an exhaust port 15 normally closed by the valve forming flange 16 which seats against the head 11 and which projects radially outwardly from one end of the sleeve 16, this sleeve forming a stem for the valve and projecting through the guide 17 which is formed on the upper wall of the section 11. An inlet port 18 communicates with the inlet chamber or manifold 18 formed in the section 10. Formed in the sleeve 16 are openings '19 whereby the fuel delivered to the chamber 18 may enter the sleeve 16. Secured to the upper end of the sleeve 16 is a head 20 having the peripheral flange 21 engaging one end of the spring 22 which embraces the sleeve 16f and engages at its opposite end the upper wall of the section 11 so as to normally retain the valve 16 in closing position.

Projecting downwardly from the head 20 is a sleeve 23 and projecting upwardly therefrom is a sleeve 22, this sleeve 22 projecting through the upper wall of the section 10. These sleeves serve as a guide for the valve stem 25 which projects upwardly therefrom and is attached to the head 24;, this valve head engaging a seat formed on the end of the sleeve so as to control the flow of the fuel into the chamber 96. Mounted fixedly on the sleeve 22 is a cap 26 engaging a fork 27 mounted on the rocker arm 28. This rocker arm 28 is rockably mounted on the shaft 29 and connects to a push rod 30 which extends downwardly and is reciprocated by a suitable cam shaft with a cam arrangement. This cam shaft and cam arrangement is not shown as it may be of any well known type and of itself forms no specific part of the invention.

Embracing the upper end of the rod 25 is a coil spring 31, one end of which engages the upper surface of the cap 26 and the other end of which engages the washer 32 which is mounted on the valve stem 25. The upper end of the valve stem 25 is engaged by the czi end of the rocker arm 33 which is rockably mounted upon the shaft 34 and which is actuated by the push rod 35. Mounted on the shaft 3- are springs 36 which serve to retain the rocker arm 33 normally in engagement with the upper end of the valve stem 25. Mounted in the rocker arm 28 is an adjustment screw 37 and a similar adjustment screw 38 is mounted in the rocker arm 33.

In operation, when the push rod is moved upwardly the engagement of the rocker arm 28 with the cap 26 will force the sleeve 16' downwardly so as to move the valve 16 away from its seat and permit scavenging of the cylinder 96. In this movement the valve Qt will remain in the position shown in Fig. 1.

After the scavenging has been effected and the valve 16 returned to its seat, as shown in Fig. l, and the rocker arm 33 is rocked by an actuation of the push rod 35, the valve 24L will move downwardly from its seat to permit the fuel passing through the openings 19 to enter the cylinder 96.

By this structure there is provided a large exhaust valve so that a maximum area of exhausting is presented and a most eificient scavenging of the cylinder effected.

By forming the head in the two sections indicated, an easy and simple structure is provided for adjustment, removal or replacement of the various parts forming he valve structure.

With this type of structure there is also provided a concentric arrangement of the intake and exhaust control valves, this concentric arrangement permitting a compact structure, and affording an eficient and durable device in operation.

While I have illustrated and described the preferred form of my invention, I do not wish to limit myself to the precise details of structure shown, but desire to avail myself of such variations and modifications as come within the scope of the appended claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A valve structure of the class described, comprising: a tubular member; a radially projecting valve-forming flange adjacent one end of said tubular member for closing an eX- haust port communicating with a cylinder with which used; a head mounted on the opposite end of said tubular member, said tubular member having lateral openings formed therein adjacent said head and communicating with an intake manifold of said engine; a valve stem extended axially of said tubularmember and projected through said head; extensions at opposite sides of said head for forming guides for said valve stem, one of said extensions projecting beyond the outer surface of said head; a valve head carried by said stem and engaging one end of said sleeve for controlling communication of said intake manifold with said cylinder; a cap on the upper of said extensions; a peripheral flange on said head; a spring engaging said flange for normally retaining said first mentioned valve in closing position; a spring engaging said cap for normally retaining said second mentioned valve in position; actuating means for moving said first mentioned valve to open position; and actuating means for moving said second mentioned valve to open position.

2. In aninternal combustion engine of the class described having a cylinder: a head section mounted on said cylinder having a port formed therein adapted for communication with said cylinder and provided with an exhaust port; an upper head section mounted on said first mentioned head section and provided with an intake port; a tubular member slidably mounted and projected into each of said head sections and provided with openings communicating with said upper head section; a peripheral flange on the lower end of said tubular member providing a valve for closing the cylinder communicating port of said first mentioned head section; a head mounted on the upper end of said tubular member; tubular extensions projected centrally outwardly from opposite sides of said head one of said extensions projecting outwardly through said upper head section; a valve head for closing the lower end of said tubular member; a valve stem on said valve head projected through said extensions and extending exteriorly of said upper head section a spring in said upper head section retaining the valve portion on said tubular member in closing position; and a spring exterior of said head sections for normally retaining said valve head in closing position.

In testimony whereof I have signed the foregoing specification.

LAWRENCE ROBERTSON. 

